Electrically-controlled switch.



A. s; GUBITT. ELEGTBIGALLY GONTBOLLED SWITCH.

APPLICATION FILED APBJB, 190a.

Patented 0013. 20, 1908.

Witnesses I 5 41 Kin-9 UNITED STATES PATENT OFFICE.

AROHIBALD S. CUBIIT, OF SGH'ENEG'IAIIY, NEW YORK, ASSIGNOR TO GENERALELECTRIC COMPANY, A CORPORATION OI NEW YORK.

ELECTRICALLY-CONTROLLED SWITCH. r

To all whom it may concern:

Be it known that I, AnoHmALn; S. Contra, a subjectof the King of GreatBritain, residing tudy, State of Nw Yorlohave invented certain new anduseful. Improvements in Electrically-ControlledSwitches, of which thefollowing is a specification.

In connection with certain forms of electrical apparatus electricallycontrolled switches areused in which a current carrying coil is'employed 'for maintaining the at which the holding coil releases maybevaried by means operable from a distance.

It is an object of my invention to provide means for satisfyingthis needin a simple and ellicientmanner.

My invention is particularly adapted for use in connection with relaysin which a movable core is by some means moved to a certain position andheld there-at by the magnetizing effect of-afholding coil. Such relaysare often employed in connection with s stems-of coutrol for dynai'noelcctric Ina-- c nnes in which a plurality; of electricallyi controlledswitches are arranged ,to operate in succession .for the purposeofeflecting certain desired connections in the circuits of the controlledapparatus. For example, in certain systems of motor control now wellknown to those skilled in thisart the resistance interposed in themotorcircuit on starting is automatically removed sectio rby-section bymeans of a plurality of electrically-controlled switches which operatesuccessively under the control of a so-ealled notching-relay whichinterrupts the actucircuit for the switches aft'er theopcratron of eachswitch and-maintains said atin circuit interrupted as long as thecurrent in the motor circuit exceeds a certain-"value. It is to theserelays that my invention isespecially applicable, and theneedfor'itferises especially where, because of inequalities 'in the loadupon the controlled apparatus','it is Specification of Letters Patent.

Application filed April 22, 1908. Serial No. 428,628.

at Schenecta dy,' county of Schenec-,

Patented on. 20, 1908.

desirable to vary the llinit of current permissible in the circuits ofthe controlled apparatus and thereby regulate the rate of acceleration.I

Systems of control in which the cutting out of the starting resistancein the motor circuit takes place automaticaly are now used to a largeextent in the operation of electrically-driven;vehicles, such as carsand locomotives, and it is in this line of work that my invention isespecially useful.

In the following description and in the drawing I have described andillustrated a notching relay having my invention embodied therein, but Ido not wish to be understood aslilniting it to this application since itmay be used in many other connections, as will be obvious to thosefamiliar with this art.

The drawing illustrates in front elevation a notchi ng relay hai ing myinvent-ion incof Ora-ted therein. i

Re erring to the drawing, 1' is a back plate of any su1tiibljeinsulating material upon which are mounted the various parts of thedevice;

2 is the iron? frame: of the rela secured in any suitableunannerto thebaci plate 1,

within which frameis an actuating coil 3 of insulated wire and a holdingcoil 4 of heavy conductor. Arranged formovement within the coils?) and 4isa core 5 of magnetic material carrying near its lower end a- 'steel"contact disk fiwhich when the core is in the position shown bridgesfixed contacts 7 and 8 of magnetic material. The contact disk 6 isslidingly arranged upon an extension 9 of the core 5 between a shoulder10 ands sprin 11. Coils 12 and 13surround the fixe contacts 7 and 8, resectively, and are connected in series with 't ese contacts and serve to(produce a magnetic field which retains the isk 6 in engagement with thecontacts 7 and 8 durin the first part of the upward movement 0? thecore, thereby delaying the o nm of the contacts and also giving a quicbrea A fixed core 15 of magnetic material is screwed into the top of theframe 2, being held in position by a set screw '16. This core protectsinto the own in the the coil 3 as s di i iviii g i the movable core 5rod 1'1 extends upward from and is connectedat its ,upper end to themovable member 18 of a dash-pot 19. This dash-pot allows the movablecore to rise freely but retards it in its downward movement. I

The parts of the relay so far described,

- except for a slight change in the rod 17,

. herelnafter mentioned, may be of any suit! able and well-known form.

Secured in any suitable manner, either to the frame 2 or directly to theback plate 1,

, is a frame 21' in which at 22 is pivoted a lever 23 through a hole inwhich the upper reduced portion 24 of the rod 17 freely passes, asclearly shown in the drawin A.

Washer 25 maybe provided on the reduced )ortion 2 1 of the rod 17between the shouler formed by the larger part of the rod 17 I and thelever 23. The lever 23 carries at its outer end an armature 26 ofmagnetic mate rial which when the lever is in the position shown in fulllines bridges the oles of an phosphor-bronze in order to preventsticking 1 core 5'."

of the armature to the magnet when the latter is deenergiz'cd. The steeldisk 6 and the fixed contacts 7 and 8' may besilver plated on theircooperating surfaces for the same reason and in order to insure goodelectrical contact at these points The last two mentionedexpedient's'are well-known.

The operation of the device is as follows: When current passes throughthe actuating coil 3, which may be connected in series with the coils l2and 13 and the contacts 7 and 8 as shown, the core 5 rises into themagnetic field produced, and if the the et 27 1s deiingerized-the lever23 will be 1i (1 to the posltionshown in dotted lines. The air gapbetween the top of the movable core 5 and the fixed core 15 will then besmall and ajcurrent of a certain value in the coil 4will be required tohold the core in this raised" position after the disk 6. has brokenengagement with contacts 7"and 8, thereby interrupting thecircuitthrough the coil 3. If, however, the magnet 27 is energized priorto the energization ofthe actuatingcoil 3, the armatilre lti will beheld down in engagement with the magnet and thellever '23 willbe enga edby the washer 25 and will serve tostop teupward movement 'of theThe-core 5 will, therefore, have a new limit-to its upwardmovement'and'the gap existing after'operation between the top ofthe core5' and the bottom of the core 15 willbe greater than'it was when thecore was free to .rnove ,upward its maximum amount unimtpcded by thelever 23. By increasing in is way the ga which exists betweenthscoresaand-law the'corefi is in its upper position, the permeabilityof the magnetic circuit of the holding coil 4 is decreased and a largercurrent is required in the coil 4 to hold the core 5 in its, upperposition. This means that when a relay equipped as shown is used asanotching relay 1n a system of control, it may be controlled from adistance by energizing or deenergizin the ma net 27 and will give twolimits ey ond w ich if the current in the motor circuit is increased,further cutting out of resistance will be prevented. By locating theswitch which controls the energization of the coil 28 near the pointfrom which the operator controls the system the change is easily madefrom operation at one current-limit to operation at the-other.

What I claim as new anddesire to secure by Letters Patent of the UnitedStates, is,

i 1. In a switch, a current carrying coil, a core movable in the fieldthereof, means for moving said core into the field of said coil-, andmeans operable from a distance for varying the permeability of themagnetic circuit of said coil.

2. In a switch, a current carrying holding coil, a core movable in thefield thereof, means foamoving said core into the field of said holdingcoil, and means operable from a distance for varying the permeability'ofthe magnetic circuit through the movable core.

3. In a relay, a current carrying actuating coil, a current carryingholding coil, acor movable in the, fields of said coils and ar-,

ranged to be moved by" said actuating coil and held by said holdingcoil, and means operable from a distance for varying the permeability ofthe magnetic circuit of the holding coi 4. In a relay, a currentcarrying actuating coil, a current carrying holding coil, a core movablein the fieldsof said coils and arranged to be moved b said actuatingcoil.

and held by said holding coil, a fixe lcore of magnetic material towardwhich the movable core .moves, and'ineans operable from a distance forvaryin the "ap existing between the movable an 'fi'x movable core hasbeen moved to its extreme position towardssaid fixed core.

6. In a relay, a current carrying actuating coil, a currentcarryingholding' coil, :1 core of magneticmaterial movable in the fieldsof sai coils and arranged to be moved by said actuating coil and coil, afixed core of ma etic material toward which said movab core rnovm, and

cores when. the

eld by said holding of said coils and arranged to be mov means operablefrom a distance for varying the limitof movement of the toward the fixedcore.

.7. In a relay, a current carrying actuating cull, a current carryingholding coil, a core of magnetic material mbvable in the fields of saidcoils am, arranged to be moved by said actuating coil, a fixed coretoward which said movable core moves, and electromagnetieally operatedmeans for varying the gap existing between said movable and movable corefixed cores after said movable core has been moved to its extremeposition toward said fixed core.

' 8. In a relay, a current carrying actuating coil, a current carryingholding coil, a core of magnetic material movable in the lds y saidactuating coil and held by said'holding coil, a fixed core ofmagnetic'material toward which said movable core moves, and

elect-romagnetically operated means for .varyingthe limitof movement ofsaid movthe limit of movement of said movable core toward said fixedcore. y

In Witness whereof, I have hereunto set my hand this 21st day of April,1908. I

ARCHIBALD. S. CUllllT. Witnesses I BENJAMIN 1-5. Hum, HELEN ()nrom).

coils, contacts opened by said core in

